Determination of histidine decarboxylase mRNA in various rat tissues by the polymerase chain reaction

Abstract

Histidine decarboxylase (HDC) mRNA in various rat tissues were quantitated by using a reverse transcription-polymerase chain reaction (RT-PCR) in which a mouse mRNA was used as an internal standard. The stomach HDC mRNA level was the highest followed by the brain, skin, jejunum, spleen and liver. There was no measurable HDC mRNA in the kidney. The stomach HDC activity was also the highest followed by the brain, skin, spleen, jejunum, liver and kidney. A significant correlation (r = 0.940, p < 0.0001) was observed between the HDC mRNA levels and HDC activities in these tissues. We have also examined the HDC mRNA levels in fasting rats and found that HDC mRNA levels in the stomach were reduced after the 48-hr-fasting with the decrease in HDC activities. These observations indicate that there may exist a gene regulation, at least at the basal level, for the HDC activities in the rats.

Overexpression of histamine H4 receptors in the kidney of diabetic rat

“…Histamine is a biogenic amine that exerts many (patho)physiological effects through its interaction with four subtypes of G-protein-coupled receptors, designated H [1][2][3][4] , which are differentially expressed in various tissues and cell types. It is synthesized from L-histidine through the catalytic activity of the rate-limiting enzyme histidine decarboxylase (HDC).…”

“…Although HDC is principally expressed in mast cells, the most important source of histamine, it is well recognized that a number of other cell types, such as tuberomammillary nucleus (TMN) neurons in the brain and parietal cells in the stomach [1], also express this enzyme. Notably, HDC expression has been also reported in the kidney, where it was found in the proximal tubule [2], thus in keeping with the demonstrated ability of the kidney to produce histamine.…”

Titel

“…Bands were observed in samples isolated from HAoSMC and HAEC with the expected product size. The band observed in RNA samples extracted from rat liver, previously shown to contain HDC [4], was identical in size to the bands observed in both HAoSMC and HAEC. In addition, no band was observed for RNA samples extracted from rat kidney which is also consistent with previous findings [4].…”

“…In the present experiments, liver and kidney were selected to serve as positive and negative controls according to results obtained by Kondo et al [4]. Detection of HDC mRNA in liver tissue (positive control) may result from vascular tissue present in the organ and/or the presence of HDC mRNA in other hepatic cells.…”

“…In previous studies, HDC mRNA has been detected in various tissues isolated from the rat including the stomach, skin, spleen, liver [4] and cultured rat brain microvascular endothelial cells [5]. The objective of this study was to investigate histamine synthesis capability of human vascular smooth muscle and endothelial cells by determining the presence of HDC mRNA.…”